Frequency response analysis of soil-structure interaction for concrete gravity dams

The seismic evaluation of existing dams is a major issue that was even more highlighted by the recent events in Italy. In this regard, researchers and engineers need a reliable and quick tool to assess the complex behaviour of the dam – reservoir – soil system. COMSOL Multiphysics® [1] is able to effectively perform a coupled study in the frequency domain by using both Structural Mechanics and Acoustic modules and offers the possibility to simulate the unboundedness of the half space terrain and reservoir. In this paper the soil-structure interaction for concrete gravity dams is considered, investigating its effect on the dynamic response of a 2D system under earthquake excitation. More specifically, the advantages of considering the semi unbounded domains will be shown. To this purpose the results in terms of structural response will be obtained under different boundary conditions and modelling approaches.